My puppy was the same - she would scratch me to death if I had failed the first time and tried again!
I havent given liquid medicine before but if i did i would try a syringe. make sure his head is tilted up so he doesn't spit it out and I would put it in the corner of his lips (if you know what i mean). remember on a counter he can slip around and move backwards. I would say sit him in your lap so you can grip on to him. wow, that sounds harsh but I mean just so that you can keep him still! lol!
When i started brushing my Yorkie's teeth she was the same. they need to just learn it isnt hurting them, although im sure the medication tastes vile. try some treats and reward him for sitting still. sit him on your lap facing away from you and have the syringe in his sight and let him see it. He's just scared and you can't blame him for that.
when i started to clip my Yorkie's hair she was terrified of the clippers. i always keep something she likes to eat close by and reward her for positive behaviour. I also started by touching her with the clippers while they were off and then putting it on the counter while they were on and eventually moving them to her body. i know it's off the topic but i would think the same rule applies to anything that scares him. he needs to see the syringe won't hurt him and be rewarded for the things he does right
when i give a pill i always try to hide it in something but it gets spat out! i normally sit on the floor with her between my knees holding her still. if they facing you they just back out and run off!
good luck
remember, baby steps. these things are so easy for us as humans but a little puppy doesnt understand why you are doing it!